Studies on the mechanism of flagellar motility.

鞭毛运动机制的研究。

基本信息

批准号：
03640596
负责人：
SHINGYOJI Chikako
金额：
$ 1.34万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03640596/
关键词：
Flagellar motility sperm microtubule sliding velocity 「9+2」構造滑り運動屈曲面

项目摘要

The movement of eukaryotic cilia and flagella is characterized by rhythmic generation of bending waves. There is ample evidence that mechanical and chemical conditions influence the frequency of the flagellar oscillation, however, no systematic investigation has been made so far on the effect of changing the beat frequency on other parameters of flagellar movement, because no reliable method has been available with which one can either increase or decrease the beat frequency reversibly.Our introduction of imposed head vibration of a sperm (Gibbons et al., 1987) allowed us to manipulate the flagellar beat frequency reversibly. In the present study, the heads of demembranated spermatozoa of the sea urchin Tripneustes gratilla, reactivated at different concentrations of ATP, were held by suction in the tip of a micropipette and vibrated laterally with respect to the head axis. This imposed vibration resulted in a stable rhythmic beating of the reactivated flagella that was synchronized to … More the frequency of the micropipette. The reactivated flagella, which in the absence of imposed vibration had an average beat frequency of 39 Hz at 2 mmol 1^<-1> ATP, showed stable beating synchronized to the pipette vibration over a range of 20-70 Hz. At ATP concentrations of 10-100 mumol 1^<-1>, the range of vibration frequency capable of maintaining stable beating was diminished; increase in the ATP concentration above 2 mmol 1^<-1> had no effect on the range of stable beating. In flagella reactivated at ATP concentrations above 100 mumol 1^<-1>, the apparent time-averaged sliding velocity of axonemal microtubules decreased when the imposed frequency was below the unimposed flagellar beat frequency, but at higher imposed frequencies it remained constant, with the higher frequency being accompanied by a decrease in bend angle. This maximal sliding velocity at 2 mmol1^<-1> ATP was close to the sliding velocity in the distal region of live sperm, possibly indicating that it represents an inherent limit in the velocity of active sliding. The results are consistent with the view that the sliding velocity of axonemal microtubules does not depend solely upon the local concentration of ATP, but is also dependent upon the oscillatory mechanism associated with initiation of new flagellar bends. Less

真核纤毛和鞭毛的运动的特征是有节奏的弯曲波。有足够的证据表明机械和化学条件会影响鞭毛振荡的频率，但是，到目前为止，没有进行系统性投资，因为它改变了节拍频率对鞭毛运动的其他参数的影响，因为没有可靠的方法可以使用可靠的方法或降低节拍频率。我们引入了精子的施加头部振动（Gibbons等，1987）使我们能够可逆地操纵鞭毛频率。在本研究中，通过在微孔管的尖端中假设，以不同浓度的ATP重新激活的海胆三环gratilla的精子的头部持有，并相对于头轴横向振动。这种施加的振动导致了重新激活的鞭毛的稳定节奏，该节奏同步到……更大的微孔频率。在没有施加振动的情况下，重新激活的鞭毛在2 mmol 1^<-1> ATP时的平均节拍频率为39 Hz，显示在20-70 Hz范围内稳定的节拍与移液振动同步。在10-100 Mumol 1^<-1>的ATP浓度下，能够维持稳定节拍的振动频率范围降低。在2 mmol 1^<-1>以上的ATP浓度的增加对稳定节拍范围没有影响。在鞭毛以高于100 mumol 1^<-1>以上的ATP浓度重新激活的鞭毛中，当施加的频率低于未强加的鞭毛频率时，轴突微管的明显时间平均滑动速度降低，但是在较高强加的频率下，它保持恒定，它保持恒定，较高的频率伴随着较高的频率在弯头角度下。在2 mmol1^<-1> ATP处的最大滑动速度接近实时精子远端区域的滑动速度，这可能表明它代表了活动滑动速度的继承极限。结果与以下观点一致：轴突微管的滑动速度不仅取决于ATP的局部浓度，但也取决于与新的Flagllar弯曲启动相关的振荡机制。较少的